1. Field of the Invention
The present invention relates to a device for testing the performance accuracy of an automotive collision avoidance radar system providing frequency modulation (FM) continuous wave (CW) radar signals.
2. Description of the Related Art
Recently, manufacturers such as Bosch of Germany have begun manufacturing collision avoidance radar systems for automobiles. A collision avoidance radar operating in a FM/CW mode transmits a signal from an antenna typically located in the grill area of an automobile. The collision avoidance radar then determines from the frequency shift of a return signal received by the antenna a distance an object causing the return signal is located from the automobile. Systems in the United States are configured to operate within a 76-77 GHz frequency band allocated by the Federal Communications Commission (FCC) for collision avoidance radar systems.
To assure proper performance of a collision avoidance radar system, the device must be regularly tested. Testing is performed to assure the collision avoidance radar system is operating within the 76-77 GHz range specified by the FCC. Testing is also performed to assure that the system is radiating adequate power. Such testing is typically performed by connecting a test receiver to an oscillator of a collision avoidance radar system. A disadvantage of testing a point prior to the antenna, however, is that any errors due to the antenna will not be detected.
Test measurements are further made to assure that the collision avoidance radar system is making proper calculations of distance to an object creating a return signal. Such testing is typically performed by placing a 1.sup.2 meter metal spherical standard at desired distances from the collision avoidance radar system, and checking that the radar system accurately indicates the distances. However, a disadvantage of utilizing the 1.sup.2 meter standard for a simulator is the large area required for simulation as well as awkwardness of moving the 1.sup.2 meter standard relative to the collision avoidance system.